Natural motion tuned for distance. The Women's Nike Free RN Distance 2 Running Shoe features enlarged auxetic technology and a Lunarlon cushioning system to provide flexibility and comfort that lasts from mile 1 to done. Lunarlon cushioning system features soft, reengineered Lunarlon foam for a smooth, cushioned transition. It is fused to a lightweight IU carrier to deliver an excellent blend of plush cushioning and durable support underfoot.The auxetic tristars offer 6 different flex points for the ultimate in natural motion. Expanding and contracting equally in all directions, the auxetic shapes allow equal pressure dispersal throughout your stride.